Is there a way to connect a 2.5” Header collector to a stock CAT?

Planning to go for a JDM 4-1 header with a 2.5” collector. Not planning to change the stock CAT now…. I agree that gains with the stock restrictive CAT will be minimal but wouldn’t want to do it now because of the auto-x class I am running in.


What is the best way to connect a 2.5” collector to a stock GSR CAT?

Thanks



Modified by schumi at 7:02 PM 7/20/2005

 

i dont know of a way you can do that to a stock cat. just buy a carsound hi flo cat.

 

total no-no...best to get the whole header cat exhaust first...i'm thinking that some exhaust might come back up to the engine with that setup because your collector is too big for a stock cat...

 

i took my stock cat to a muffler shop and they welded 2.5" flanges on both ends its still pretty restictive, but i only use it for smog purposes..i have a carsound high flow cat that i use for daily driving and i can totally tell the difference in high rpms

 

The whole point is that I cannot change the stock CAT because of the auto-x class I am running in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by schumi &raquo;</TD></TR><TR><TD CLASS="quote">The whole point is that I cannot change the stock CAT because of the auto-x class I am running in.</TD></TR></TABLE>

In that case, I would suggest going with a quality header with a 2" collector rather than a "JDM-style" header.

 

get a 2.5" resonated test pipe and weld on the stock heat shields...they won't know the difference...

 

I think noise would be a factor, plus its not your regular ol officials at the local drag strip

 

I think its best to be within the rules but explore the maximum potential.

Anyways, a muffler shop will not be able to help me on this?

 

anyone?